1. Field of the Invention
The invention relates to a pull-cable type opening and closing device for sunroofs and the like, and to a cable drive mechanism for use in the same.
2. Description of the Related Art
Typically, so-called a geared-cable type opening and closing device has been used for opening and closing an opening in the ceiling of an automobile, such as a sunroof and the like. This opening and closing device has such a construction that, as shown in FIG. 13, it converts a driving force of a motor M via a gear 101 into a reciprocating motion of a right-and-left pair of geared cables 102, to reciprocally drive a roof lid 103 fixed at the tips or the front ends of these geared cables 102 along roof rails 104 in a front and rear directions of the automobile, thus opening and closing an opening 106 in the roof 105. The right-and-left geared cables 102 are guided by guide pipes 107 in a sliding manner.
Japanese Patent Laid-Open Publication No. Hei 3-11924, on the other hand, discloses therein a pull-cable type opening and closing device. As shown in FIG. 14, this type of opening and closing device comprises a pair of drums 110 which are rotary-driven in the right-and-left directions by the motor M, a closed-loop shaped right-and-left pair of pull-cables (wires) 111 which are wound onto these respective drums and sent out to be driven reciprocally and circularly, lid brackets 112 which are coupled somewhere along these respective pull-cables, and rails 113 for guiding these lid brackets back and forth in a sliding manner. To the lid brackets 112 is attached a lid 115 for opening and closing an opening 114. At the tip of each of the rails 113 is attached in a rotating manner a pulley 116 for reversing the direction of the pull-cables 111.
With this, when the drum 110 rotates in an arrow direction, one end of the corresponding pull-cable 111 is wound onto that drum, feeding out the other end. When the right and left pull cables 111 are thus circularly driven in a synchronous manner, the right and left lid brackets move in an arrow direction, to retract the lid 111, thus opening the opening the 114. When the motor M rotates in a reverse direction, the opening is closed similarly.
In the above-mentioned geared-cable type opening and closing device, the guide pipes 107 for guiding the geared cables 102 have rigidity and the motor M for evenly driving the right and left geared cables 102 and the gear 101 need to be provided at a center position between the rails 104, so that the layout has a low degree of freedom. Also, a reaction force of the geared cables 102 is put into the motor M, thus giving rise to a force to cause it to rotate with the gear 101 as a center. This leads to need for providing a motor bracket strong enough to stand that force, thus making the device heavy and expensive in terms of manufacturing cost. Further, sliding sound is raised when the geared cables 102 slide in the guide pipe 107, striking sound is raised when the geared cables return to strike the inner surface of the guide pipe 107, creaking sound is raised at the linking portion between the geared cables 102 and the gear 101, and other working noise is raised loud.
The above-mentioned pull-cable type opening and closing device, on the other hand, has the motor M and the drums 110 provided at the center position between the right and left rails 113, so that it has a low degree of freedom. Moreover, it needs to have the two drums 110 for winding cables onto themselves and driving respective right and left pull-cables 111, so that its drive unit becomes large-sized, thus making it heavy and expensive in manufacturing cost.
In view of the above, it is an object of the present invention to provide an opening and closing device for sunroofs and the like that has a high degree of freedom of the layout of the drive unit and the like, and that is light in weight and inexpensive in manufacturing cost.
According to the present invention, there is provided a pull-cable type opening and closing device for sunroofs and the like which comprises a pair of rails running in parallel with each other, a lid reciprocating along these rails for opening and closing an opening in a ceiling and the like, right and left pull-cables having ends engaged to the lid and arranged along the rails, and a drive mechanism for reciprocally driving these pull cables, wherein the pull-cables are arranged in a closed loop in which one of pull-cable coming out of the above-mentioned drive mechanism is arranged from the base end side of the first rail to its tip side along the rail, with engaging to the lid at a middle portion thereof, furthere beeing arranged from another end of the first rail to the base end side of the second rail along a route bypassing the opening, then beeing arranged from the base end side of that second rails to its tip side along the rail with beeing engaged to the lid at middle portion thereof, and further beeing arranged from the tip side of the second rail along a route bypassing the opening back to the drive mechanism.
In the case of such an opening and closing device, the pull-cable may be arranged from the tip side of the first rail to the base end side of the second rail along any route as far as they bypass the opening. For example, the pull-cables may be arranged from the tip side of the first rail using a conduit to the tip side of the second rail and then along the second rail to its base end and turned back there, then to the tip side as mentioned above. Also, the route along which the pull-cables are turned back from the tip side of the second rail to the drive mechanism is not limited to the above-mentioned one, so that these pull-cable may be turned back from the tip side of the second rail to the tip side of the first rail using a conduit and then further turned back along the first rail to its base end side, then to the drive mechanism Further, preferably, these bypass routes are combined so that these two pull-cables may be guided between the base end side of the first rail and the drive mechanism using flexible conduits.
Also, as for the bypass route, the above-mentioned pull-cable may be turned back at the tip portion of the first rail and arranged along the first rail to the base end side and then, using a conduit, to the base end side of the second rail or they may be turned back at the tip side of the second rail and, along the second rail, to the end side and then back to the drive mechanism. Further, more preferably, these routes are combined so that the pull-cables may be guided between the base end side of each of these rails and the drive mechanism using conduits having flexibility.
In the case where two pull-cables are to be arranged reciprocally along one rail in any of the above-mentioned constructions, that first rail or second rail is preferably provided with an open cross-sectional portion for passing one of the pull-cables that is engaged with a lid and a closed cross-sectional portion for guiding in a sliding manner the other pull-cable that is not engaged with the lid. In the case of an opening and closing device in which the cables are turned back at the end portion of the rail, preferably, a pulley is provided in a rotary manner at the end portion of the first or second rail for rotating the pull-cables and, near the pulley, a guide is provided for making a spacing between the pull-cables engaged at the pulley smaller than the diameter of the pulley. Further, preferably, at the end portion of the first or second rail, the pulley for turning back the pull-cables is provided in a rotary manner as well as in such a manner as to be adjusted in the rail direction. Also, preferably, the above-mentioned rail having the open cross-sectional portion is provided with an elastonomer-made lip for preventing the chord oscilation or chord vibration of the pull-cable.
A cable drive mechanism according to the invention is a mechanism for driving a pull-cable, in winding and feeding, of a pull-control cable consisting of a pull-cable coupled to a driven member for transmitting pulling force and a conduit standing a compressing force. The cable driving mechanism comprises a housing having a drum therein for winding the pull-cable and driving them, an outer-end, having a stopping portion and a spring-engaging portion, which is provided at the pull-cable inlet/outlet of the housing in such a manner as to be movable in the pull-cable extending direction and also at which the end portion of the conduit is engaged, a spacer disposed between the housing and the outer-end""s stopping portion for defining an end of motion of the outer-end toward the housing side, and a compression spring disposed between the spacer and the outer-end""s spring-engaging portion.
In such a cable drive mechanism, in a preferable case, the above-mentioned outer-end is a cylindrical member comprising a sliding portion inserted in an axially-movable manner through a hole formed in the housing in a pull-cable arranging direction, a spring holding portion which continues therefrom via a stopping step portion constituting the above-mentioned stopping portion and which has a larger diameter than the sliding portion, and a flange portion constituting the above-mentioned spring-engaging portion, the above-mentioned spacer preferably being a tubular member having a step to be engaged with the outer-end""s stopping step portion. Also, preferably, the above-mentioned housing is provided with an engaging step portion to be engaged with the spacer""s end portion for aligning the spacer.
The opening and closing device according to the present invention employs pull-cables and so gives rise to lower level of noise. Also, the pull-cable passing along the first rail and the pull-cable passing along the second rail substantially continue with each other, to construct one closed loop, thus requiring only one drive mechanism for circulatory-driving a cable loop, for example, a motor-driven winding drum. This opening and closing device, therefore, is reduced in mounting space, lighter, and more inexpensive in manufacturing cost. Also, it is capable of adjusting cable loosening and tension basically at one position. Moreover, it has a smaller drive mechanism and so has a higher degree of freedom in layout.
The opening and closing device having the pull-cable arranged from the tip side of the first rail to the tip side of the second rail using a conduit and then, along the second rail, to its base end side can safely hold the pull-cables where they are arranged along the second rail, thus having good integrated unit form and being easy to handle. Also, in the case of turning the pull-cables from the tip side of the second rail using a conduit back to the tip side of the first rail and, along the first rail, to its base end and then back to the drive mechanism, the turned-back cable goes along the first rail, thus providing easy handling as a unit. Also, two cables, going and coming back each, couple the first rail""s base end portion and the drive mechanism, thus providing a higher degree of freedom in arrangement layout for the drive mechanism.
Also, in the case where the above-mentioned bypass routes are combined to use a flexible conduit to guide the two pull-cables between the first rail""s base and the drive mechanism, the first and second rails are coupled at their top ends using two conduits and so are done the first rail""s base end side and the drive mechanism, thus providing a further higher degree of freedom of layout. Also, the cables are turned back only at one portion on the base end side of the second rail, thus providing a higher transmission efficiency.
In the case where the above-mentioned pull-cables are turned back at the tip portion of the first rail and arranged along it to the base end side and then, using a conduit, to the base end side of the second rail, the reciprocating two cables can be supported by the first rail, thus providing easy handling. Also, in the case where the pull-cables are turned back at the tip side of the second rail and, along it, arranged back to the base end side and then back to the drive mechanism side, the reciprocating two cables can be supported by the second rail, thus providing easy handling. Further also, in the case where these bypass routes are combined to use flexible conduit for guiding the pull-cables between the base end side of each rail and the drive mechanism, the pull-cables are stretched only at the base end side of the first and second rails, to couple the rails and the drive mechanism with the flexible conduits, thus providing easy handling and a high degree of freedom in layout.
In the case where two cables are arranged to reciprocate along one rail, when the first or second rail is provided with an open cross-sectional portion for passing one of the pull-cables engaged with a lid and a closed cross-sectional portion for guiding, in a sliding manner, the other pull-cable not engaged with the lid (claim 4), the closed cross-sectional portion serves to guide the pull-cable in a sliding manner, thus securely accommodating the reaction force of the pull-cable. With this also, the lid interference resistance and water resistance can be obtained easily.
Further, in the case where an opening and closing device in which the pull-cables are turned back at the rail end portion is provided, at the rail end portion, with a rotary pulley for rotating the pull-cables and, near that pulley, with a guide engaged with that pulley for making the spacing between the pull-cables smaller than the pulley diameter, it is possible to reduce that spacing between the cables while maintaining a large radius of curvature of the pull-cables. With this, the degree of freedom can be improved at the point where the cables are positioned.
In the case where the pulley is provided in a position-adjustable manner in the direction of the rail, it is easy to adjust the cable loosening and tension. Also, in the case where the above-mentioned rail having the open cross-sectional portion is provided, in a contacting manner, with an elastomer-made lip for preventing the chord oscsilation of the pull-cables, the pull-cables vibration can be suppressed, thus reducing the noise.
In the cable drive mechanism according to the invention, if the pull-cable has loosened, the spring urges the outer-end to move away from the housing. With this, the substantial arrangement length of the pull-cable becomes longer so as to absorb the loosening thereof, thus restoring the tension of the pull-cable. Also, a spacer is provided, so that the outer-end can have a longer stroke without changing the spring mounting length. Therefore, even rather the arrangement length of the pull-cable becomes long, for example, a pull-cable type opening and closing device for sunroofs and the like can be accommodated sufficiently. That is, only by exchanging the spacer and the outer-end for an ordinary cable drive mechanism, it can be suitable used as the cable drive mechanism of an opening and closing device for sunroofs and the like.
In the case where the above-mentioned outer-end is a cylindrical member which comprises a sliding portion inserted in an axially-movable manner through a hole formed in the housing in a pull-cable arrengement direction, a spring holding portion which continues therefrom via a stopping step constituting the above-mentioned stopping portion and which has a larger diameter than the sliding portion, and a flange which constitutes the above-mentioned spring stopping portion in such a manner that the above-mentioned spacer is a tubular member having a step to be engaged with the stopping step of the outer-end, the spring is held in the same manner as with a cable drive mechanism using no spacer and so can be shared in use. Also, in the case where the above-mentioned housing is provided with a stopping step engaged with the spacer""s end portion for alignment of the spacer, it is easy to align and mount the spacer.